Toxic changes in the anatomy and function of the retina, the tissue at the back of the eye responsible for sensing light and relaying visual signals to the brain, have been demonstrated to occur as a result of both developmental and adult exposure to lead. The electroretinogram (ERG) is a non-invasive method of assessing the functional status of the retina. The ERG is a complex electrical waveform recorded with an electrode placed on the surface of the cornea. Recent mathematical models of the ERG relate the recorded waveform to the neural events which occur when light is absorbed by the retina under conditions of light and dark adaptation. Using these models of the ERG, we will assess the mechanisms, location, and severity of the effects of lead exposure on the mammalian retina. We hope to generalize these results to the effects of neurotoxic exposures on the human visual system.